Most folks arrested for DUI in Washington State will be asked to submit to a breath alcohol content (BAC) test at the police station. The Alcotest 9510 or “Draeger” machine will likely be the machine you’re asked to blow on since it replaced the old Datamaster in Washignton State several years ago. Most people facing the choice of submitting to the breath test or refusing will choose to blow because the consequences to your driver’s license are more severe if you refuse.

The Draeger machine will print out the results of your breath test after you blow. There are a lot of different readings on the printout, but the most important ones are the readings under “Subject Sample 1” and “Subject Sample 2.” A valid evidentiary breath test requires two separate breath samples. The Draeger machine uses two separate technologies – infrared spectroscopy and electrochemical cell – to measure the amount of alcohol on each of your two breath samples. This means your breath test printout will have four slightly different readings for your BAC.

The old Washington State DUI statutes said your legal breath test measurement was the lowest result. However, that language has been removed leaving the courts and Department of Licensing (DOL) free to use any combination of the four readings as your legal breath test result. This means that even if one of your results is below the legal limit, you may still be facing a full battle in both the court case and separate DOL case.

The Draeger printout shows several other readings besides your subject sample results. These additional readings are blank tests, internal standard and external standard. Under Washington State law the machine must run these additional tests in order for your BAC test to be considered legally valid. They are all important, but the most important readings will always be the four results listed under your two subject samples.

If you or a friend are facing a DUI whether it’s a breath test, refusal or a blood draw, then you owe it to yourself to consult with an experienced DUI attorney. Call Cooney Law Offices today. We can help!